Toner cartridges are used in a variety of xerographic apparatuses including printers, copiers, facsimile machines, and devices which combine these three functions in a single device. A toner cartridge typically consists of a toner hopper ultrasonically welded to a developer roller housing, and removably attached to a waste bin section. During transportation the toner is confined to the toner hopper by a removable seal. Upon the toner cartridges"" arrival at its final destination, the end user removes a seal allowing toner to move from the toner hopper to the developer roller.
Seals are used by original equipment manufacturers to seal new toner cartridges, and are also used by remanufacturers of toner cartridges. A remanufacturer takes a used toner cartridge, cleans it, replaces any worn out components, adds new toner, and then sells the resulting product to an end user as a remanufactured cartridge. Such remanufactured cartridges are typically sold at a discount to new cartridges.
The purpose of the seal is to ensure that toner does not migrate from the toner hopper during shipping. Toner is a fine, dry powder. If it is not confined to the toner hopper it will migrate throughout the package and may damage other components of the cartridge. Such toner migration will also create an esthetically unpleasant mess for the end user. If the toner is not confined to the toner hopper the end user will end up with toner on their hands and clothes.
A variety of seals have been used to seal or reseal toner cartridges. Many OEMs use a heat seal of a single strip of clear plastic material over the toner hopper. The OEM, and many remanufacturers after them, have also used a gasket seal assembly similar to that depicted in U.S. Pat. No. 5,223,068. This seal assembly has a gasket of a stiff material such a polystyrene heat-sealed to a removable seal, typically a polyethylene. The gasket is then attached by glue or other adhesive to the toner hopper sealing surface. The end user pulls on the tail of the removable seal exposing the gasket opening and thus allowing toner to migrate from the toner hopper to the developer roller.
While seals assemblies of this kind are common, they offer challenges particularly to the remanufacturer. The stiff plastic gasket does not seal well. Particularly for narrow cartridges it is difficult to place properly.
The seal assembly disclosed in U.S. Pat. No. 5,223,068 is most easily used where the toner hopper has been separated from the developer roller section as disclosed in that patent.
U.S. Pat. No. 5,523,828 discloses, but does not claim, a gasket seal covered with a seal material. The gasket is described as being made of an open cell foam, and the seal is a polyethylene ribbon material. This patent adds an additional layer of stiff material removably attached to the gasket, which acts as a support or handle to facilitate maneuvering the seal assembly into position.
While the maneuverability of this seal is an advantage over the prior gasket seal, the seal is expensive to construct because of the need for the additional layer of material, which is the support. Furthermore, in order to manufacture this seal assembly this support must be placed on the seal assembly by hand rather than as a step in an automated process. In addition, the layer of stiff material must be removed and thrown away before the cartridge may be used, creating disposal issues. The present invention improves on these seal assemblies by making an easy to maneuver, easy to automate seal assembly. The present invention relates to an improved seal assembly for new toner cartridges as well as for remanufactured toner cartridges.
This invention relates to a seal assembly for toner cartridge used in xerographic devices such as printers, copiers, facsimile machines, and all-in-one devices that combine all three functions. The seal assembly is designed to be easily remaneuverable, and capable of being manufactured in an automated process. The seal assembly is further designed for remanufacturers, although original equipment manufacturers may find the device useful. The seal assembly generally comprises a substantially rigid gasket with a rectangular slot in the center of the gasket forming the gasket opening. A removable seal lies over the gasket. The gasket has a handle formed on one side of it. In the preferred embodiment the gasket and handle are made integrally of the same material. The removable seal is made of a material which tears preferentially in a given orientation. In the preferred embodiment the removable seal is integral with a tail. The end user grasps the handle to maneuver the seal assembly over the toner hopper discharge opening. After the seal assembly is installed, the tail of the seal assembly on the toner hopper is laid back over the removable seal and is placed through an opening between the toner hopper and the developer roller housing. The end user pulls the tail. This causes the removable seal to be removed from over the toner hopper discharge opening. In the preferred embodiment the removable seal material tears in the direction in which the tail is being pulled exposing an opening substantially the same size as the toner hopper discharge opening. The gasket may be thought of as having two sides. In the preferred embodiment the removable seal extends across the width of the gasket slot on the first side of the gasket. On the second side of the gasket is a layer of pressure sensitive adhesive. Over the layer of pressure sensitive adhesive on the opposite side of the gasket parallel to the gasket and the pressure sensitive adhesive layer is a removable release liner.
In one embodiment of the invention the handle is perforated to facilitate removal of the handle after the seal is installed and the handle no longer serves a function. In an alternate embodiment the handle has a layer of adhesive on its surface to allow the handle to be attached to the edge of the seal assembly after the seal assembly is installed by folding the handle over and pressing the handle down, attaching the handle out of the way after it has been used. The handle is sized so as to allow it to be laid over the cover, but not block the area of the cover which is removed when the tail of the seal is pulled.